This invention relates to a sewing machine in general, and more particularly to a device for automatically balancing a feed reference point of the sewing machine.
In a fabric feeding mechanism of the sewing machine, there is a predetermined feed reference point of a feed dog which will repeatedly move from the feed reference point in the forward and rearward directions to produce a number of stitches forming a specific stitch pattern design. In this connection, it will be inevitable that the repeated use of the sewing machine in a long time of period will cause the abrasion of the fabric feeding mechanism at certain parts thereof, especially at the joint parts of the interconnecting link elements through which the feed reference point is determined. As the result, the feed reference point will be displaced from an optimum position, and the pattern of stitches formed with the forward and rearward feeding will be considerably deformed. Especially, with an electronically operated sewing machine capable of storing so many data for the pattern designs to be stitched, various patterns may be produced which requires a considerable number of stitches formed with the forward and rearward feeding amounts being applied. In this case, such a displacement of the feed reference point in the feeding mechanism will greatly deform the pattern with accumulation of so many feeding errors.